alex marquardt, abc news, cairo. >>> and back here at home we want to tell you about another food alert out tonight and this one is about pork. a big consumer report study found a high rate of contamination in pork chops and ground pork from a kind of bacteria that can send you to the emergency room. abc's dr. richard besser brings us the whole picture. >> reporter: you don't know its name, but you may be 1 of the 100,000 americans who get sick each year from bacteria called yersinia. and today's study explains why. "consumer reports" tested pork, the types you'd buy in the supermarket, including pork chops and ground pork and they found that nearly 70% of the samples they tested had the dangerous bacteria yersinia on it. ground pork turned out to be even more risky than pork chops. >> this should be a wake-up call to the american public in terms of what are we doing in terms of monitoring the safety of pork and what can we do in the future? >> reporter: this bacteria can hit hard. in a matter of days, you'll experience fever, cramps, and bloody diarrhea that may last for weeks, especia